By ANN PRINGLE HARRIS; ANN PRINGLE HARRIS is a writer who teaches English at the Fashion Institute of Technology in New York.

Published: January 10, 1988

You can get that raised-eyebrow response even from natives of the country that has given cullen skink its -well, its modest claim to fame.

''You'll have a hard time finding that in a restaurant,'' said a hotelier in the heart of the Pertshire highlands. ''Expatriate Scots love to talk about the dishes they had at home. They'll go on for hours about stovies'' (potatoes cooked with the meat and drippings of a leftover roast), ''but even their mothers probably wouldn't cook that way any more.''

A slightly more promising view came from Douglas Philp, a Dundee business executive and an aficionado of Scottish cooking. ''Go to Cullen,'' he said. ''If it isn't on the menu they'll do it for you.''

It wasn't on the menu, and they did do it for us, but by then it had become apparent that the difficulties of finding this Scottish fish soup were somewhat exaggerated and that it really wasn't necessary to drive 120 miles up the coast unless you had other reasons for doing so. (Actually, there are many other reasons for doing so.) In recent years the Scots have begun to overcome any inferiority complex they may have had about their cuisine (Why should haggis be a joke to people who've never even seen it?) and to offer their specialties side by side with those of French or Italian provenance. Cullen skink now appears on menus in many restaurants where chefs are adept at preparing traditional Scottish dishes. Nor does it suffer by comparison with fish soups of New England or Mediterranean origin; it is entirely different, but equally tasty.

As with single-malt whisky and Drambuie, Scotland's famed liqueur, the main characteristic of cullen skink is its smokiness, which comes from its basic ingredient, finnan haddock. Whereas soupe de poisson has the tomato-herb-garlic flavor of provencal cooking, and New England fish chowder tastes fresh and briny, cullen skink mingles the sweetness of fresh whole milk with the smokiness of cured fish. You sniff as you taste, and the soup pleases the senses with a blend of flavors and fragrances not often encountered together.

Preparation of cullen skink calls for simmering a smoked haddock and chopped onion in equal parts of water and milk, removing the fish from the bones, making a stock of the pot liquor, fish bones and trimmings, simmering and straining the stock, then thickening it to a spoon-coating consistency with mashed potato (Scottish chefs rush to the challenge of leftovers, including yesterday's mashed potatoes). Finally, the flaked fish is added with, often, a topping of cream or melted butter and chopped parsley or watercress.

One cook asserted that cullen skink should be made only in winter, when there is a good supply of old potatoes, which have a drier consistency when mashed.

Some recipes specify a finnan haddock caught in the Moray Firth for cullen skink and, indeed, the best of the soups we sampled was at an inn on the Firth. The bits of fish had not been completely pureed; they remained flaky and tender, adding texture to the liquid. Moray Firth haddock, we were told, is less likely to be cured with a vegetable dye, as is often the case with finnan haddock from farther south. As a result, it is paler than the color-added finnans, but, say its fans, tenderer and more delicate in flavor.

Finding the origin of the name cullen skink proved more of a challenge than finding the soup. One cookbook declared that skink meant stew and that cullen was a species of fish - which is a species of fantasy, or if you prefer, nonsense. Cullen, as we discovered for ourselves, is a picturesque fishing and resort town on the Moray Firth; it was there that we ate our most memorable soup, but exactly why the soup takes its name from the town no one I asked was able to explain.

Skink has a more traceable history. Webster's Third International says that skink, as derived from the Greek, denotes a small lizard. Since there are no small lizards involved in the preparation of cullen skink, we move to another meaning of the word: liquor or essence, as derived from Middle High German and often denoting a thin, weak beer. Hence the word skinker for a pourer or tapster.

The linguistic evolution from skink as a weak alcoholic liquor to skink as a nonalcoholic broth seems logical, except that skink broth, according to the Oxford English Dictionary, was made from a shin of beef. From that point on, one person's conjecture is as good as another's, or one man's meat is another's haddock. Although cullen skink is served in many parts of Scotland, it is a specialty of the eastern coastal regions, from Aberdeen up to the Moray Firth. Besides good fishing, the lowland parts of the region have rich pasture lands, so that at an inn with a good kitchen, such as the Seafield Arms in Cullen, fish soup can be followed by a fillet of prime Scottish beef that equals any to be found in a New York steak house. The Seafield Arms is an attractive, homey inn - the sort of place where guests tend to gather before dinner and swap stories. It also has a good wine list for its size. South and west from Cullen, along the River Spey, through beautiful highland scenery, one comes to Pitlochry, and then to Perth. Pitlochry makes much of its salmon ladder, a series of pools rising to the level of Loch Faskally, in which salmon can move upstream to their spawning grounds. An informal poll of recent visitors suggests that you will be fortunate if you find a salmon.

But you can be sure of finding cullen skink, simply by continuing on A9 through Perth, and south for about nine miles to the Bein Inn in Glenfarg. Here, cullen skink is always on the menu, together with a complete selection of Scottish dishes ranging from kipper pate through River Tay poached salmon, Scottish beefsteak flamed in whisky, and on down to cloutie dumpling. (Here the dining room is more attractive than the guest accommodations.) Having worked our way through cullen skink - creamy and thick - and poached salmon served with ample helpings of three local vegetables, we asked the waiter to explain about cloutie dumpling. ''It's like a Christmas pudding,'' he said, ''but a wee bit richer.''

We decided to let it go till next time. A DINER'S SAMPLER

Among the restaurants and inns that offer cullen skink are the Bein Inn in Glenfarg, Perthshire (216), the Cedar Restaurant of the Park Hotel in Montrose, Angus (73415), and the Howtowdie Restaurant, 27A Stafford Street, Edinburgh (225-6291). All served good soup at about $2.90 (the Bein Inn and the Park Hotel) to $4.50 (the Howtowdie).

At the Seafield Arms in Cullen (40791) the soup was prepared to order on very short notice, which may account for the fact that the potatoes were sliced and not mashed. Purists might protest, but though a slight departure from the traditional recipe, this version was outstanding for its fragrant aroma and smoky taste. As an appetizer, it costs $1.90.